Dave Jarvis' Repositories

* XML transformation using XSLT3 or older

* 使用XSLT3或更早版本的XML文档转换

  // XML and XSL

  implementation 'net.sf.saxon:Saxon-HE:10.3'

* Michael Kay, [XSLT Processor](http://www.saxonica.com/)

                             Mozilla Public License

                                  Version 2.0

1. Definitions

   1.1. “Contributor”

          means each individual or legal entity that creates, contributes

          to the creation of, or owns Covered Software.

   1.2. “Contributor Version”

          means the combination of the Contributions of others (if any)

          used by a Contributor and that particular Contributor’s

          Contribution.

   1.3. “Contribution”

          means Covered Software of a particular Contributor.

   1.4. “Covered Software”

          means Source Code Form to which the initial Contributor has

          attached the notice in Exhibit A, the Executable Form of such

          Source Code Form, and Modifications of such Source Code Form, in

          each case including portions thereof.

   1.5. “Incompatible With Secondary Licenses”

          means

         a. that the initial Contributor has attached the notice described

            in Exhibit B to the Covered Software; or

         b. that the Covered Software was made available under the terms

            of version 1.1 or earlier of the License, but not also under

            the terms of a Secondary License.

   1.6. “Executable Form”

          means any form of the work other than Source Code Form.

   1.7. “Larger Work”

          means a work that combines Covered Software with other material,

          in a separate file or files, that is not Covered Software.

   1.8. “License”

          means this document.

   1.9. “Licensable”

          means having the right to grant, to the maximum extent possible,

          whether at the time of the initial grant or subsequently, any

          and all of the rights conveyed by this License.

   1.10. “Modifications”

          means any of the following:

         a. any file in Source Code Form that results from an addition to,

            deletion from, or modification of the contents of Covered

            Software; or

         b. any new file in Source Code Form that contains any Covered

            Software.

   1.11. “Patent Claims” of a Contributor

          means any patent claim(s), including without limitation, method,

          process, and apparatus claims, in any patent Licensable by such

          Contributor that would be infringed, but for the grant of the

          License, by the making, using, selling, offering for sale,

          having made, import, or transfer of either its Contributions or

          its Contributor Version.

   1.12. “Secondary License”

          means either the GNU General Public License, Version 2.0, the

          GNU Lesser General Public License, Version 2.1, the GNU Affero

          General Public License, Version 3.0, or any later versions of

          those licenses.

   1.13. “Source Code Form”

          means the form of the work preferred for making modifications.

   1.14. “You” (or “Your”)

          means an individual or a legal entity exercising rights under

          this License. For legal entities, “You” includes any entity that

          controls, is controlled by, or is under common control with You.

          For purposes of this definition, “control” means (a) the power,

          direct or indirect, to cause the direction or management of such

          entity, whether by contract or otherwise, or (b) ownership of

          more than fifty percent (50%) of the outstanding shares or

          beneficial ownership of such entity.

2. License Grants and Conditions

  2.1. Grants

   Each Contributor hereby grants You a world-wide, royalty-free,

   non-exclusive license:

    a. under intellectual property rights (other than patent or trademark)

       Licensable by such Contributor to use, reproduce, make available,

       modify, display, perform, distribute, and otherwise exploit its

       Contributions, either on an unmodified basis, with Modifications,

       or as part of a Larger Work; and

    b. under Patent Claims of such Contributor to make, use, sell, offer

       for sale, have made, import, and otherwise transfer either its

       Contributions or its Contributor Version.

  2.2. Effective Date

   The licenses granted in Section 2.1 with respect to any Contribution

   become effective for each Contribution on the date the Contributor

   first distributes such Contribution.

  2.3. Limitations on Grant Scope

   The licenses granted in this Section 2 are the only rights granted

   under this License. No additional rights or licenses will be implied

   from the distribution or licensing of Covered Software under this

   License. Notwithstanding Section 2.1(b) above, no patent license is

   granted by a Contributor:

    a. for any code that a Contributor has removed from Covered Software;

       or

    b. for infringements caused by: (i) Your and any other third party’s

       modifications of Covered Software, or (ii) the combination of its

       Contributions with other software (except as part of its

       Contributor Version); or

    c. under Patent Claims infringed by Covered Software in the absence of

       its Contributions.

   This License does not grant any rights in the trademarks, service

   marks, or logos of any Contributor (except as may be necessary to

   comply with the notice requirements in Section 3.4).

  2.4. Subsequent Licenses

   No Contributor makes additional grants as a result of Your choice to

   distribute the Covered Software under a subsequent version of this

   License (see Section 10.2) or under the terms of a Secondary License

   (if permitted under the terms of Section 3.3).

  2.5. Representation

   Each Contributor represents that the Contributor believes its

   Contributions are its original creation(s) or it has sufficient rights

   to grant the rights to its Contributions conveyed by this License.

  2.6. Fair Use

   This License is not intended to limit any rights You have under

   applicable copyright doctrines of fair use, fair dealing, or other

   equivalents.

  2.7. Conditions

   Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted

   in Section 2.1.

3. Responsibilities

  3.1. Distribution of Source Form

   All distribution of Covered Software in Source Code Form, including any

   Modifications that You create or to which You contribute, must be under

   the terms of this License. You must inform recipients that the Source

   Code Form of the Covered Software is governed by the terms of this

   License, and how they can obtain a copy of this License. You may not

   attempt to alter or restrict the recipients’ rights in the Source Code

   Form.

  3.2. Distribution of Executable Form

   If You distribute Covered Software in Executable Form then:

    a. such Covered Software must also be made available in Source Code

       Form, as described in Section 3.1, and You must inform recipients

       of the Executable Form how they can obtain a copy of such Source

       Code Form by reasonable means in a timely manner, at a charge no

       more than the cost of distribution to the recipient; and

    b. You may distribute such Executable Form under the terms of this

       License, or sublicense it under different terms, provided that the

       license for the Executable Form does not attempt to limit or alter

       the recipients’ rights in the Source Code Form under this License.

  3.3. Distribution of a Larger Work

   You may create and distribute a Larger Work under terms of Your choice,

   provided that You also comply with the requirements of this License for

   the Covered Software. If the Larger Work is a combination of Covered

   Software with a work governed by one or more Secondary Licenses, and

   the Covered Software is not Incompatible With Secondary Licenses, this

   License permits You to additionally distribute such Covered Software

   under the terms of such Secondary License(s), so that the recipient of

   the Larger Work may, at their option, further distribute the Covered

   Software under the terms of either this License or such Secondary

   License(s).

  3.4. Notices

   You may not remove or alter the substance of any license notices

   (including copyright notices, patent notices, disclaimers of warranty,

   or limitations of liability) contained within the Source Code Form of

   the Covered Software, except that You may alter any license notices to

   the extent required to remedy known factual inaccuracies.

  3.5. Application of Additional Terms

   You may choose to offer, and to charge a fee for, warranty, support,

   indemnity or liability obligations to one or more recipients of Covered

   Software. However, You may do so only on Your own behalf, and not on

   behalf of any Contributor. You must make it absolutely clear that any

   such warranty, support, indemnity, or liability obligation is offered

   by You alone, and You hereby agree to indemnify every Contributor for

   any liability incurred by such Contributor as a result of warranty,

   support, indemnity or liability terms You offer. You may include

   additional disclaimers of warranty and limitations of liability

   specific to any jurisdiction.

4. Inability to Comply Due to Statute or Regulation

   If it is impossible for You to comply with any of the terms of this

   License with respect to some or all of the Covered Software due to

   statute, judicial order, or regulation then You must: (a) comply with

   the terms of this License to the maximum extent possible; and (b)

   describe the limitations and the code they affect. Such description

   must be placed in a text file included with all distributions of the

   Covered Software under this License. Except to the extent prohibited by

   statute or regulation, such description must be sufficiently detailed

   for a recipient of ordinary skill to be able to understand it.

5. Termination

   5.1. The rights granted under this License will terminate automatically

   if You fail to comply with any of its terms. However, if You become

   compliant, then the rights granted under this License from a particular

   Contributor are reinstated (a) provisionally, unless and until such

   Contributor explicitly and finally terminates Your grants, and (b) on

   an ongoing basis, if such Contributor fails to notify You of the

   non-compliance by some reasonable means prior to 60 days after You have

   come back into compliance. Moreover, Your grants from a particular

   Contributor are reinstated on an ongoing basis if such Contributor

   notifies You of the non-compliance by some reasonable means, this is

   the first time You have received notice of non-compliance with this

   License from such Contributor, and You become compliant prior to 30

   days after Your receipt of the notice.

   5.2. If You initiate litigation against any entity by asserting a

   patent infringement claim (excluding declaratory judgment actions,

   counter-claims, and cross-claims) alleging that a Contributor Version

   directly or indirectly infringes any patent, then the rights granted to

   You by any and all Contributors for the Covered Software under

   Section 2.1 of this License shall terminate.

   5.3. In the event of termination under Sections 5.1 or 5.2 above, all

   end user license agreements (excluding distributors and resellers)

   which have been validly granted by You or Your distributors under this

   License prior to termination shall survive termination.

6. Disclaimer of Warranty

   Covered Software is provided under this License on an “as is” basis,

   without warranty of any kind, either expressed, implied, or statutory,

   including, without limitation, warranties that the Covered Software is

   free of defects, merchantable, fit for a particular purpose or

   non-infringing. The entire risk as to the quality and performance of

   the Covered Software is with You. Should any Covered Software prove

   defective in any respect, You (not any Contributor) assume the cost of

   any necessary servicing, repair, or correction. This disclaimer of

   warranty constitutes an essential part of this License. No use of any

   Covered Software is authorized under this License except under this

   disclaimer.

7. Limitation of Liability

   Under no circumstances and under no legal theory, whether tort

   (including negligence), contract, or otherwise, shall any Contributor,

   or anyone who distributes Covered Software as permitted above, be

   liable to You for any direct, indirect, special, incidental, or

   consequential damages of any character including, without limitation,

   damages for lost profits, loss of goodwill, work stoppage, computer

   failure or malfunction, or any and all other commercial damages or

   losses, even if such party shall have been informed of the possibility

   of such damages. This limitation of liability shall not apply to

   liability for death or personal injury resulting from such party’s

   negligence to the extent applicable law prohibits such limitation. Some

   jurisdictions do not allow the exclusion or limitation of incidental or

   consequential damages, so this exclusion and limitation may not apply

   to You.

8. Litigation

   Any litigation relating to this License may be brought only in the

   courts of a jurisdiction where the defendant maintains its principal

   place of business and such litigation shall be governed by laws of that

   jurisdiction, without reference to its conflict-of-law provisions.

   Nothing in this Section shall prevent a party’s ability to bring

   cross-claims or counter-claims.

9. Miscellaneous

   This License represents the complete agreement concerning the subject

   matter hereof. If any provision of this License is held to be

   unenforceable, such provision shall be reformed only to the extent

   necessary to make it enforceable. Any law or regulation which provides

   that the language of a contract shall be construed against the drafter

   shall not be used to construe this License against a Contributor.

10. Versions of the License

  10.1. New Versions

   Mozilla Foundation is the license steward. Except as provided in

   Section 10.3, no one other than the license steward has the right to

   modify or publish new versions of this License. Each version will be

   given a distinguishing version number.

  10.2. Effect of New Versions

   You may distribute the Covered Software under the terms of the version

   of the License under which You originally received the Covered

   Software, or under the terms of any subsequent version published by the

   license steward.

  10.3. Modified Versions

   If you create software not governed by this License, and you want to

   create a new license for such software, you may create and use a

   modified version of this License if you rename the license and remove

   any references to the name of the license steward (except to note that

   such modified license differs from this License).

  10.4. Distributing Source Code Form that is Incompatible With Secondary

  Licenses

   If You choose to distribute Source Code Form that is Incompatible With

   Secondary Licenses under the terms of this version of the License, the

   notice described in Exhibit B of this License must be attached.

Exhibit A - Source Code Form License Notice

     This Source Code Form is subject to the terms of the Mozilla Public

     License, v. 2.0. If a copy of the MPL was not distributed with this

     file, You can obtain one at https://mozilla.org/MPL/2.0/.

   If it is not possible or desirable to put the notice in a particular

   file, then You may include the notice in a location (such as a LICENSE

   file in a relevant directory) where a recipient would be likely to look

   for such a notice.

   You may add additional accurate notices of copyright ownership.

Exhibit B - “Incompatible With Secondary Licenses” Notice

     This Source Code Form is “Incompatible With Secondary Licenses”, as

     defined by the Mozilla Public License, v. 2.0.

"\${SCRIPT_SRC}/${ARG_JAVA_DIR}/bin/java" ${OPT_JAVA} -jar "\${SCRIPT_SRC}/${FILE_APP_JAR}" "\$@" 2>&1 >/dev/null &

   * (e.g., Markdown, XML, etc.).

    TEXT_MARKDOWN, TEXT_R_MARKDOWN, TEXT_R_XML, UNDEFINED

  );

  /**

   * Prevents re-instantiation of processing classes.

   */

  private final Map<TextResource, Processor<String>> mProcessors =

    new HashMap<>();

  private final Workspace mWorkspace;

  /**

   * Groups similar file type tabs together.

   */

  private final Map<MediaType, TabPane> mTabPanes = new HashMap<>();

  /**

   * Stores definition names and values.

   */

  private final Map<String, String> mResolvedMap =

    new HashMap<>( MAP_SIZE_DEFAULT );

  /**

   * Renders the actively selected plain text editor tab.

   */

  private final HtmlPreview mPreview;

  /**

   * Provides an interactive document outline.

   */

  private final DocumentOutline mOutline = new DocumentOutline();

  /**

   * Changing the active editor fires the value changed event. This allows

   * refreshes to happen when external definitions are modified and need to

   * trigger the processing chain.

   */

  private final ObjectProperty<TextEditor> mActiveTextEditor =

    createActiveTextEditor();

  /**

   * Changing the active definition editor fires the value changed event. This

   * allows refreshes to happen when external definitions are modified and need

   * to trigger the processing chain.

   */

  private final ObjectProperty<TextDefinition> mActiveDefinitionEditor =

    createActiveDefinitionEditor( mActiveTextEditor );

  /**

   * Tracks the number of detached tab panels opened into their own windows,

   * which allows unique identification of subordinate windows by their title.

   * It is doubtful more than 128 windows, much less 256, will be created.

   */

  private byte mWindowCount;

  /**

   * Called when the definition data is changed.

   */

  private final EventHandler<TreeModificationEvent<Event>> mTreeHandler =

    event -> {

      final var editor = mActiveDefinitionEditor.get();

      resolve( editor );

      process( getActiveTextEditor() );

      save( editor );

    };

  private final DocumentStatistics mStatistics;

  /**

   * Adds all content panels to the main user interface. This will load the

   * configuration settings from the workspace to reproduce the settings from

   * a previous session.

   */

  public MainPane( final Workspace workspace ) {

    mWorkspace = workspace;

    mPreview = new HtmlPreview( workspace );

    mStatistics = new DocumentStatistics( workspace );

    mActiveTextEditor.set( new MarkdownEditor( workspace ) );

    open( bin( getRecentFiles() ) );

    viewPreview();

    setDividerPositions( calculateDividerPositions() );

    // Once the main scene's window regains focus, update the active definition

    // editor to the currently selected tab.

    runLater( () -> getWindow().setOnCloseRequest( ( event ) -> {

      // Order matters here. We want to close all the tabs to ensure each

      // is saved, but after they are closed, the workspace should still

      // retain the list of files that were open. If this line came after

      // closing, then restarting the application would list no files.

      mWorkspace.save();

      if( closeAll() ) {

        Platform.exit();

        System.exit( 0 );

      }

      else {

        event.consume();

      }

    } ) );

    register( this );

  }

  @Subscribe

  public void handle( final TextEditorFocusEvent event ) {

    mActiveTextEditor.set( event.get() );

  }

  @Subscribe

  public void handle( final TextDefinitionFocusEvent event ) {

    mActiveDefinitionEditor.set( event.get() );

  }

  /**

   * Typically called when a file name is clicked in the {@link HtmlPanel}.

   *

   * @param event The event to process, must contain a valid file reference.

   */

  @Subscribe

  public void handle( final FileOpenEvent event ) {

    final File eventFile;

    final var eventUri = event.getUri();

    if( eventUri.isAbsolute() ) {

      eventFile = new File( eventUri.getPath() );

    }

    else {

      final var activeFile = getActiveTextEditor().getFile();

      final var parent = activeFile.getParentFile();

      if( parent == null ) {

        clue( new FileNotFoundException( eventUri.getPath() ) );

        return;

      }

      else {

        final var parentPath = parent.getAbsolutePath();

        eventFile = Path.of( parentPath, eventUri.getPath() ).toFile();

      }

    }

    runLater( () -> open( eventFile ) );

  }

  @Subscribe

  public void handle( final CaretNavigationEvent event ) {

    runLater( () -> {

      final var textArea = getActiveTextEditor().getTextArea();

      textArea.moveTo( event.getOffset() );

      textArea.requestFollowCaret();

      textArea.requestFocus();

    } );

  }

  @Subscribe

  @SuppressWarnings( "unused" )

  public void handle( final ExportFailedEvent event ) {

    final var os = getProperty( "os.name" );

    final var arch = getProperty( "os.arch" ).toLowerCase();

    final var bits = getProperty( "sun.arch.data.model" );

    final var title = Messages.get( "Alert.typesetter.missing.title" );

    final var header = Messages.get( "Alert.typesetter.missing.header" );

    final var version = Messages.get(

      "Alert.typesetter.missing.version",

      os,

      arch

        .replaceAll( "amd.*|i.*|x86.*", "X86" )

        .replaceAll( "mips.*", "MIPS" )

        .replaceAll( "armv.*", "ARM" ),

      bits );

    final var text = Messages.get( "Alert.typesetter.missing.installer.text" );

    // Download and install ConTeXt for {0} {1} {2}-bit

    final var content = format( "%s %s", text, version );

    final var flowPane = new FlowPane();

    final var link = new Hyperlink( text );

    final var label = new Label( version );

    flowPane.getChildren().addAll( link, label );

    final var alert = new Alert( ERROR, content, OK );

    alert.setTitle( title );

    alert.setHeaderText( header );

    alert.getDialogPane().contentProperty().set( flowPane );

    alert.setGraphic( ICON_DIALOG_NODE );

    link.setOnAction( ( e ) -> {

      alert.close();

      final var url = Messages.get( "Alert.typesetter.missing.installer.url" );

      runLater( () -> fireHyperlinkOpenEvent( url ) );

    } );

    alert.showAndWait();

  }

  /**

   * TODO: Load divider positions from exported settings, see bin() comment.

   */

  private double[] calculateDividerPositions() {

    final var ratio = 100f / getItems().size() / 100;

    final var positions = getDividerPositions();

    for( int i = 0; i < positions.length; i++ ) {

      positions[ i ] = ratio * i;

    }

    return positions;

  }

  /**

   * Opens all the files into the application, provided the paths are unique.

   * This may only be called for any type of files that a user can edit

   * (i.e., update and persist), such as definitions and text files.

   *

   * @param files The list of files to open.

   */

  public void open( final List<File> files ) {

    files.forEach( this::open );

  }

  /**

   * This opens the given file. Since the preview pane is not a file that

   * can be opened, it is safe to add a listener to the detachable pane.

   *

   * @param file The file to open.

   */

  private void open( final File file ) {

    final var tab = createTab( file );

    final var node = tab.getContent();

    final var mediaType = MediaType.valueFrom( file );

    final var tabPane = obtainTabPane( mediaType );

    tab.setTooltip( createTooltip( file ) );

    tabPane.setFocusTraversable( false );

    tabPane.setTabClosingPolicy( ALL_TABS );

    tabPane.getTabs().add( tab );

    // Attach the tab scene factory for new tab panes.

    if( !getItems().contains( tabPane ) ) {

      addTabPane(

        node instanceof TextDefinition ? 0 : getItems().size(), tabPane

      );

    }

    getRecentFiles().add( file.getAbsolutePath() );

  }

  /**

   * Opens a new text editor document using the default document file name.

   */

  public void newTextEditor() {

    open( DOCUMENT_DEFAULT );

  }

  /**

   * Opens a new definition editor document using the default definition

   * file name.

   */

  public void newDefinitionEditor() {

    open( DEFINITION_DEFAULT );

  }

  /**

   * Iterates over all tab panes to find all {@link TextEditor}s and request

   * that they save themselves.

   */

  public void saveAll() {

    mTabPanes.forEach(

      ( mt, tp ) -> tp.getTabs().forEach( ( tab ) -> {

        final var node = tab.getContent();

        if( node instanceof TextEditor ) {

          save( ((TextEditor) node) );

        }

      } )

    );

  }

  /**

   * Requests that the active {@link TextEditor} saves itself. Don't bother

   * checking if modified first because if the user swaps external media from

   * an external source (e.g., USB thumb drive), save should not second-guess

   * the user: save always re-saves. Also, it's less code.

   */

  public void save() {

    save( getActiveTextEditor() );

  }

  /**

   * Saves the active {@link TextEditor} under a new name.

   *

   * @param files The new active editor {@link File} reference, must contain

   *              at least one element.

   */

  public void saveAs( final List<File> files ) {

    assert files != null;

    assert !files.isEmpty();

    final var editor = getActiveTextEditor();

    final var tab = getTab( editor );

    final var file = files.get( 0 );

    editor.rename( file );

    tab.ifPresent( t -> {

      t.setText( editor.getFilename() );

      t.setTooltip( createTooltip( file ) );

    } );

    save();

  }

  /**

   * Saves the given {@link TextResource} to a file. This is typically used

   * to save either an instance of {@link TextEditor} or {@link TextDefinition}.

   *

   * @param resource The resource to export.

   */

  private void save( final TextResource resource ) {

    try {

      resource.save();

    } catch( final Exception ex ) {

      clue( ex );

      sNotifier.alert(

        getWindow(), resource.getPath(), "TextResource.saveFailed", ex

      );

    }

  }

  /**

   * Closes all open {@link TextEditor}s; all {@link TextDefinition}s stay open.

   *

   * @return {@code true} when all editors, modified or otherwise, were

   * permitted to close; {@code false} when one or more editors were modified

   * and the user requested no closing.

   */

  public boolean closeAll() {

    var closable = true;

    for( final var entry : mTabPanes.entrySet() ) {

      final var tabPane = entry.getValue();

      final var tabIterator = tabPane.getTabs().iterator();

      while( tabIterator.hasNext() ) {

        final var tab = tabIterator.next();

        final var resource = tab.getContent();

        // The definition panes auto-save, so being specific here prevents

        // closing the definitions in the situation where the user wants to

        // continue editing (i.e., possibly save unsaved work).

        if( !(resource instanceof TextEditor) ) {

          continue;

        }

        if( canClose( (TextEditor) resource ) ) {

          tabIterator.remove();

          close( tab );

        }

        else {

          closable = false;

        }

      }

    }

    return closable;

  }

  /**

   * Calls the tab's {@link Tab#getOnClosed()} handler to carry out a close

   * event.

   *

   * @param tab The {@link Tab} that was closed.

   */

  private void close( final Tab tab ) {

    final var handler = tab.getOnClosed();

    if( handler != null ) {

      handler.handle( new ActionEvent() );

    }

  }

  /**

   * Closes the active tab; delegates to {@link #canClose(TextResource)}.

   */

  public void close() {

    final var editor = getActiveTextEditor();

    if( canClose( editor ) ) {

      close( editor );

    }

  }

  /**

   * Closes the given {@link TextResource}. This must not be called from within

   * a loop that iterates over the tab panes using {@code forEach}, lest a

   * concurrent modification exception be thrown.

   *

   * @param resource The {@link TextResource} to close, without confirming with

   *                 the user.

   */

  private void close( final TextResource resource ) {

    getTab( resource ).ifPresent(

      ( tab ) -> {

        tab.getTabPane().getTabs().remove( tab );

        close( tab );

      }

    );

  }

  /**

   * Answers whether the given {@link TextResource} may be closed.

   *

   * @param editor The {@link TextResource} to try closing.

   * @return {@code true} when the editor may be closed; {@code false} when

   * the user has requested to keep the editor open.

   */

  private boolean canClose( final TextResource editor ) {

    final var editorTab = getTab( editor );

    final var canClose = new AtomicBoolean( true );

    if( editor.isModified() ) {

      final var filename = new StringBuilder();

      editorTab.ifPresent( ( tab ) -> filename.append( tab.getText() ) );

      final var message = sNotifier.createNotification(

        Messages.get( "Alert.file.close.title" ),

        Messages.get( "Alert.file.close.text" ),

        filename.toString()

      );

      final var dialog = sNotifier.createConfirmation( getWindow(), message );

      dialog.showAndWait().ifPresent(

        save -> canClose.set( save == YES ? editor.save() : save == NO )

      );

    }

    return canClose.get();

  }

  private ObjectProperty<TextEditor> createActiveTextEditor() {

    final var editor = new SimpleObjectProperty<TextEditor>();

    editor.addListener( ( c, o, n ) -> {

      if( n != null ) {

        mPreview.setBaseUri( n.getPath() );

        process( n );

      }

    } );

    return editor;

  }

  /**

   * Adds the HTML preview tab to its own, singular tab pane.

   */

  public void viewPreview() {

    viewTab( mPreview, TEXT_HTML, "Pane.preview.title" );

  }

  /**

   * Adds the document outline tab to its own, singular tab pane.

   */

  public void viewOutline() {

    viewTab( mOutline, APP_DOCUMENT_OUTLINE, "Pane.outline.title" );

  }

  public void viewStatistics() {

    viewTab( mStatistics, APP_DOCUMENT_STATISTICS, "Pane.statistics.title" );

  }

  public void viewFiles() {

    try {

      final var factory = new FilePickerFactory( mWorkspace );

      final var fileManager = factory.createModeless();

      viewTab( fileManager, APP_FILE_MANAGER, "Pane.files.title" );

    } catch( final Exception ex ) {

      clue( ex );

    }

  }

  private void viewTab(

    final Node node, final MediaType mediaType, final String key ) {

    final var tabPane = obtainTabPane( mediaType );

    for( final var tab : tabPane.getTabs() ) {

      if( tab.getContent() == node ) {

        return;

      }

    }

    tabPane.getTabs().add( createTab( get( key ), node ) );

    addTabPane( tabPane );

  }

  public void viewRefresh() {

    mPreview.refresh();

  }

  /**

   * Returns the tab that contains the given {@link TextEditor}.

   *

   * @param editor The {@link TextEditor} instance to find amongst the tabs.

   * @return The first tab having content that matches the given tab.

   */

  private Optional<Tab> getTab( final TextResource editor ) {

    return mTabPanes.values()

                    .stream()

                    .flatMap( pane -> pane.getTabs().stream() )

                    .filter( tab -> editor.equals( tab.getContent() ) )

                    .findFirst();

  }

  /**

   * Creates a new {@link DefinitionEditor} wrapped in a listener that

   * is used to detect when the active {@link DefinitionEditor} has changed.

   * Upon changing, the {@link #mResolvedMap} is updated and the active

   * text editor is refreshed.

   *

   * @param editor Text editor to update with the revised resolved map.

   * @return A newly configured property that represents the active

   * {@link DefinitionEditor}, never null.

   */

  private ObjectProperty<TextDefinition> createActiveDefinitionEditor(

    final ObjectProperty<TextEditor> editor ) {

    final var definitions = new SimpleObjectProperty<TextDefinition>();

    definitions.addListener( ( c, o, n ) -> {

      resolve( n == null ? createDefinitionEditor() : n );

      process( editor.get() );

    } );

    return definitions;

  }

  private Tab createTab( final String filename, final Node node ) {

    return new DetachableTab( filename, node );

  }

  private Tab createTab( final File file ) {

    final var r = createTextResource( file );

    final var tab = createTab( r.getFilename(), r.getNode() );

    r.modifiedProperty().addListener(

      ( c, o, n ) -> tab.setText( r.getFilename() + (n ? "*" : "") )

    );

    // This is called when either the tab is closed by the user clicking on

    // the tab's close icon or when closing (all) from the file menu.

    tab.setOnClosed(

      ( __ ) -> getRecentFiles().remove( file.getAbsolutePath() )

    );

    tab.tabPaneProperty().addListener( ( cPane, oPane, nPane ) -> {

      if( nPane != null ) {

        nPane.focusedProperty().addListener( ( c, o, n ) -> {

          if( n != null && n ) {

            final var selected = nPane.getSelectionModel().getSelectedItem();

            final var node = selected.getContent();

            node.requestFocus();

          }

        } );

      }

    } );

    return tab;

  }

  /**

   * Creates bins for the different {@link MediaType}s, which eventually are

   * added to the UI as separate tab panes. If ever a general-purpose scene

   * exporter is developed to serialize a scene to an FXML file, this could

   * be replaced by such a class.

   * <p>

   * When binning the files, this makes sure that at least one file exists

   * for every type. If the user has opted to close a particular type (such

   * as the definition pane), the view will suppressed elsewhere.

   * </p>

   * <p>

   * The order that the binned files are returned will be reflected in the

   * order that the corresponding panes are rendered in the UI.

   * </p>

   *

   * @param paths The file paths to bin according to their type.

   * @return An in-order list of files, first by structured definition files,

   * then by plain text documents.

   */

  private List<File> bin( final SetProperty<String> paths ) {

    // Treat all files destined for the text editor as plain text documents

    // so that they are added to the same pane. Grouping by TEXT_PLAIN is a

    // bit arbitrary, but means explicitly capturing TEXT_PLAIN isn't needed.

    final Function<MediaType, MediaType> bin =

      m -> PLAIN_TEXT_FORMAT.contains( m ) ? TEXT_PLAIN : m;

    // Create two groups: YAML files and plain text files.

    final var bins = paths

      .stream()

      .collect(

        groupingBy( path -> bin.apply( MediaType.fromFilename( path ) ) )

      );

    bins.putIfAbsent( TEXT_YAML, List.of( DEFINITION_DEFAULT.toString() ) );

    bins.putIfAbsent( TEXT_PLAIN, List.of( DOCUMENT_DEFAULT.toString() ) );

    final var result = new ArrayList<File>( paths.size() );

    // Ensure that the same types are listed together (keep insertion order).

    bins.forEach( ( mediaType, files ) -> result.addAll(

      files.stream().map( File::new ).collect( Collectors.toList() ) )

    );

    return result;

  }

  /**

   * Uses the given {@link TextDefinition} instance to update the

   * {@link #mResolvedMap}.

   *

   * @param editor A non-null, possibly empty definition editor.

   */

  private void resolve( final TextDefinition editor ) {

    assert editor != null;

    final var tokens = createDefinitionTokens();

    final var operator = new YamlSigilOperator( tokens );

    final var map = new HashMap<String, String>();

    editor.toMap().forEach( ( k, v ) -> map.put( operator.entoken( k ), v ) );

    mResolvedMap.clear();

    mResolvedMap.putAll( editor.interpolate( map, tokens ) );

  }

  /**

   * Force the active editor to update, which will cause the processor

   * to re-evaluate the interpolated definition map thereby updating the

   * preview pane.

   *

   * @param editor Contains the source document to update in the preview pane.

   */

  private void process( final TextEditor editor ) {

    // Ensure processing does not run on the JavaFX thread, which frees the

    // text editor immediately for caret movement. The preview will have a

    // slight delay when catching up to the caret position.

    final var task = new Task<Void>() {

      @Override

      public Void call() {

        try {

          final var p = mProcessors.getOrDefault( editor, IDENTITY );

          p.apply( editor == null ? "" : editor.getText() );

        } catch( final Exception ex ) {

          clue( ex );

        }

        return null;

      }

    };

    task.setOnSucceeded(

      e -> invokeLater( () -> mPreview.scrollTo( CARET_ID ) )

    );

    // Prevents multiple process requests from executing simultaneously (due

    // to having a restricted queue size).

    sExecutor.execute( task );

  }

  /**

   * Lazily creates a {@link TabPane} configured to listen for tab select

   * events. The tab pane is associated with a given media type so that

   * similar files can be grouped together.

   *

   * @param mediaType The media type to associate with the tab pane.

   * @return An instance of {@link TabPane} that will handle tab docking.

   */

  private TabPane obtainTabPane( final MediaType mediaType ) {

    return mTabPanes.computeIfAbsent(

      mediaType, ( mt ) -> createTabPane()

    );

  }

  /**

   * Creates an initialized {@link TabPane} instance.

   *

   * @return A new {@link TabPane} with all listeners configured.

   */

  private TabPane createTabPane() {

    final var tabPane = new DetachableTabPane();

    initStageOwnerFactory( tabPane );

    initTabListener( tabPane );

    return tabPane;

  }

  /**

   * When any {@link DetachableTabPane} is detached from the main window,

   * the stage owner factory must be given its parent window, which will

   * own the child window. The parent window is the {@link MainPane}'s

   * {@link Scene}'s {@link Window} instance.

   *

   * <p>

   * This will derives the new title from the main window title, incrementing

   * the window count to help uniquely identify the child windows.

   * </p>

   *

   * @param tabPane A new {@link DetachableTabPane} to configure.

   */

  private void initStageOwnerFactory( final DetachableTabPane tabPane ) {

    tabPane.setStageOwnerFactory( ( stage ) -> {

      final var title = get(

        "Detach.tab.title",

        ((Stage) getWindow()).getTitle(), ++mWindowCount

      );

      stage.setTitle( title );

      return getScene().getWindow();

    } );

  }

  /**

   * Responsible for configuring the content of each {@link DetachableTab} when

   * it is added to the given {@link DetachableTabPane} instance.

   * <p>

   * For {@link TextEditor} contents, an instance of {@link ScrollEventHandler}

   * is initialized to perform synchronized scrolling between the editor and

   * its preview window. Additionally, the last tab in the tab pane's list of

   * tabs is given focus.

   * </p>

   * <p>

   * Note that multiple tabs can be added simultaneously.

   * </p>

   *

   * @param tabPane A new {@link TabPane} to configure.

   */

  private void initTabListener( final TabPane tabPane ) {

    tabPane.getTabs().addListener(

      ( final ListChangeListener.Change<? extends Tab> listener ) -> {

        while( listener.next() ) {

          if( listener.wasAdded() ) {

            final var tabs = listener.getAddedSubList();

            tabs.forEach( ( tab ) -> {

              final var node = tab.getContent();

              if( node instanceof TextEditor ) {

                initScrollEventListener( tab );

              }

            } );

            // Select and give focus to the last tab opened.

            final var index = tabs.size() - 1;

            if( index >= 0 ) {

              final var tab = tabs.get( index );

              tabPane.getSelectionModel().select( tab );

              tab.getContent().requestFocus();

            }

          }

        }

      }

    );

  }

  /**

   * Synchronizes scrollbar positions between the given {@link Tab} that

   * contains an instance of {@link TextEditor} and {@link HtmlPreview} pane.

   *

   * @param tab The container for an instance of {@link TextEditor}.

   */

  private void initScrollEventListener( final Tab tab ) {

    final var editor = (TextEditor) tab.getContent();

    final var scrollPane = editor.getScrollPane();

    final var scrollBar = mPreview.getVerticalScrollBar();

    final var handler = new ScrollEventHandler( scrollPane, scrollBar );

    handler.enabledProperty().bind( tab.selectedProperty() );

  }

  private void addTabPane( final int index, final TabPane tabPane ) {

    final var items = getItems();

    if( !items.contains( tabPane ) ) {

      items.add( index, tabPane );

    }

  }

  private void addTabPane( final TabPane tabPane ) {

    addTabPane( getItems().size(), tabPane );

  }

  public ProcessorContext createProcessorContext() {

    return createProcessorContext( null, NONE );

  }

  public ProcessorContext createProcessorContext(

    final Path exportPath, final ExportFormat format ) {

    final var editor = getActiveTextEditor();

    return createProcessorContext(

      editor.getPath(), exportPath, format, editor.getCaret() );

  }

  private ProcessorContext createProcessorContext(

    final Path path, final Caret caret ) {

    return createProcessorContext( path, null, ExportFormat.NONE, caret );

  }

  /**

   * @param path       Used by {@link ProcessorFactory} to determine

   *                   {@link Processor} type to create based on file type.

   * @param exportPath Used when exporting to a PDF file (binary).

   * @param format     Used when processors export to a new text format.

   * @param caret      Used by {@link CaretExtension} to add ID attribute into

   *                   preview document for scrollbar synchronization.

   * @return A new {@link ProcessorContext} to use when creating an instance of

   * {@link Processor}.

   */

  private ProcessorContext createProcessorContext(

    final Path path, final Path exportPath, final ExportFormat format,

    final Caret caret ) {

    return new ProcessorContext(

      mPreview, mResolvedMap, path, exportPath, format, mWorkspace, caret

    );

  }

  private TextResource createTextResource( final File file ) {

    // TODO: Create PlainTextEditor that's returned by default.

    return MediaType.valueFrom( file ) == TEXT_YAML

      ? createDefinitionEditor( file )

      : createMarkdownEditor( file );

  }

  /**

   * Creates an instance of {@link MarkdownEditor} that listens for both

   * caret change events and text change events. Text change events must

   * take priority over caret change events because it's possible to change

   * the text without moving the caret (e.g., delete selected text).

   *

   * @param file The file containing contents for the text editor.

   * @return A non-null text editor.

   */

  private TextResource createMarkdownEditor( final File file ) {

    final var path = file.toPath();

    final var editor = new MarkdownEditor( file, getWorkspace() );

    final var caret = editor.getCaret();

    final var context = createProcessorContext( path, caret );

    mProcessors.computeIfAbsent( editor, p -> createProcessors( context ) );

    editor.addDirtyListener( ( c, o, n ) -> {

      if( n ) {

        // Reset the status to OK after changing the text.

        clue();

        // Processing the text may update the status bar.

        process( getActiveTextEditor() );

      }

    } );

    editor.addEventListener(

      keyPressed( SPACE, CONTROL_DOWN ), this::autoinsert

    );

    // Set the active editor, which refreshes the preview panel.

    mActiveTextEditor.set( editor );

    return editor;

  }

  /**

   * Delegates to {@link #autoinsert()}.

   *

   * @param event Ignored.

   */

  private void autoinsert( final KeyEvent event ) {

    autoinsert();

  }

  /**

   * Finds a node that matches the word at the caret, then inserts the

   * corresponding definition. The definition token delimiters depend on

   * the type of file being edited.

   */

  public void autoinsert() {

    final var definitions = getActiveTextDefinition();

    final var editor = getActiveTextEditor();

    final var mediaType = editor.getMediaType();

    final var operator = getSigilOperator( mediaType );

    DefinitionNameInjector.autoinsert( editor, definitions, operator );

  }

  private TextDefinition createDefinitionEditor() {

    return createDefinitionEditor( DEFINITION_DEFAULT );

  }

  private TextDefinition createDefinitionEditor( final File file ) {

    final var editor = new DefinitionEditor( file, createTreeTransformer() );

    editor.addTreeChangeHandler( mTreeHandler );

    return editor;

  }

  private TreeTransformer createTreeTransformer() {

    return new YamlTreeTransformer();

  }

  private Tooltip createTooltip( final File file ) {

    final var path = file.toPath();

    final var tooltip = new Tooltip( path.toString() );

    tooltip.setShowDelay( millis( 200 ) );

    return tooltip;

  }

  public TextEditor getActiveTextEditor() {

    return mActiveTextEditor.get();

  }

  public ReadOnlyObjectProperty<TextEditor> activeTextEditorProperty() {

    return mActiveTextEditor;

  }

  public TextDefinition getActiveTextDefinition() {

    return mActiveDefinitionEditor.get();

  }

  public Window getWindow() {

    return getScene().getWindow();

  }

  public Workspace getWorkspace() {

    return mWorkspace;

  }

  /**

   * Returns the sigil operator for the given {@link MediaType}.

   *

   * @param mediaType The type of file being edited.

   */

  private SigilOperator getSigilOperator( final MediaType mediaType ) {

    final var operator = new YamlSigilOperator( createDefinitionTokens() );

    return switch( mediaType ) {

      case TEXT_R_MARKDOWN, TEXT_R_XML -> new RSigilOperator(

        createRTokens(), operator );

      default -> operator;

    };